An invention created before the 20th century: The Laser

Laser (1961). This device, which uses a quantum mechanical effect, to generate a beam of light with unique properties that make that has a wide range of applications,from medicine to the automotive, telecommunications and aeronautics, was inventedin 1960 by the physicist Theodore Maiman. The English word laser comes from thelaser, an acronym for Light Amplification by Stimulate Emission of Radiation